Anoble gas consists of three isotopes of masses of 19.99 amu, 20.99 amu, and 21.99 amu. the relative abundances of these isotopes are 90.92%, 0.257%, and 8.82% respectively. what is the average atomic mass of this noble gas? what noble gas is this?

               Neon

Explanation:

Average Atomic Mass is calculated using following formula,

= [ (Mass of Isotope 1 × % Natural Abundance) + (Mass of Isotope 2 × % Natural Abundance) + (Mass of Isotope n × % Natural Abundance) ] ÷ 100

Data Given:

                    Mass of Isotope 1  =  19.99 amu

                    % Natural Abundance of Isotope 1  =  90.92

                    Mass of Isotope 2  =  20.99 amu

                    % Natural Abundance of Isotope 2  =  0.257

                    Mass of Isotope 3  =  21.99 amu

                    % Natural Abundance of Isotope 3  =  8.82

Solution:

Putting values in formula,

Average Atomic Mass  = [ (19.99 × 90.92) + (20.99 × 0.257) + (21.99 × 8.82) ] ÷ 100

Average Atomic Mass  =  (1817.49 + 5.394 + 193.95) ÷ 100

Average Atomic Mass  =  20.16

Result:

            Consulting Periodic Table it was found that the noble gas with Average Atomic Mass of 20.16 ≈ 20.18 is Neon.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.